Security readout for executives and security teams
Plain-English summary
This flaw can let a device on the same routing segment crash Cisco ASA or FTD appliances that process OSPF. A successful attack forces a reload, interrupting client traffic through the firewall. It is high urgency for networks where these firewalls run OSPF with adjacent routers.
Executive priority
Prioritize remediation where ASA or FTD firewalls protect critical traffic and run OSPF. A crash can interrupt business connectivity, but attacker positioning must be adjacent, reducing broad internet risk.
Technical view
Cisco reports improper parsing of certain options in OSPF LSA type 11 packets in ASA and FTD Software. An unauthenticated adjacent attacker can send a crafted packet to trigger device reload, causing denial of service. CVSS v3.0 is 7.4 with adjacent attack vector and high availability impact.
Likely exposure
Exposure is limited to Cisco ASA or FTD devices participating in OSPF where an attacker can reach the adjacent routing domain. Public internet exposure is not indicated by the source bundle.
Exploitation context
The bundle does not show CISA KEV listing or other evidence of active exploitation. The attack requires adjacent network positioning, no credentials, no user interaction, and low complexity once adjacency reachability exists.
Researcher notes
Focus validation on OSPF-enabled ASA and FTD deployments. The root issue is CWE-20 input validation in parsing OSPF LSA type 11 options. Avoid assuming affected versions or fixed releases beyond Cisco advisory data.
Mitigation direction
- Review Cisco advisory for affected and fixed ASA or FTD releases.
- Upgrade affected devices using Cisco-supported guidance.
- Restrict OSPF adjacency and routing segments to trusted devices.
- Monitor firewall reloads or instability linked to OSPF activity.
Validation and detection
- Inventory ASA and FTD devices running OSPF.
- Compare installed versions with the Cisco advisory.
- Confirm OSPF is not exposed to untrusted adjacent networks.
- Review logs for unexpected reloads during OSPF processing.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2019-12676 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.4 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H2.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.4HighVector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20191002 Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software OSPF LSA Processing Denial of Service VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.